Postsynaptic $\alpha_1$-, $\alpha_2$-Adrenoceptors in Rat Isolated Aorta

적출한 흰쥐 대동맥에 있어서 postsynaptic $\alpha_1$-, $\alpha_2$- 아드레날린 수용체에 관한 연구

$\alpha$-Adrenoceptor subtypes in the isolated rat aortic strips were examined by using agonists and antagonists which have varying selectivity for $\alpha_1$- and $\alpha_2$- adrenoceptors. Norepinephrine and phenylephrine produced a similar magnitude of maximum contractions. $pA_2$ values for prazosin and yohimbine were not significantly different using norepinephrine or phenylephrine as the agonist, suggesting a single population of alpha-adrenoceptor. Contractile responses produced by alpha-agonists were antagonized more effectively by prazosin (approximately 1000 fold) than by yohimbine.